The Bulgarian Constitution explicitly guarantees the Right of Association. Article 44 envisages that “Citizens shall be free to associate” as long as they do not act to the detriment of country's sovereignty, national integrity or unity of the nation and do not incite racial, national, ethnic or religious enmity or an encroachment on the rights and freedoms of the other citizens.
The provision also provides that no organisation shall establish clandestine or paramilitary structures or shall seek to attain its aims through violence
The legal framework of the right of Association is regulated mainly by the Non-profit Legal Entities Act and the procedures related to registration, submission of changes and erasure are regulated by the Commercial Register and the Register of Non-profit Legal Entities Act. The first one specifies the incorporation procedure of non-profit legal entities, the respective rules for their termination, management and relationship with the state. Under this law two main forms of NGOs in Bulgaria are recognized: Associations that are membership-based and Foundations that are property-based organizations.
Each of them could be registered either as a public benefit or as a mutual benefit organization.
Under Article 5 of the Non-profit Legal Entities Act, Founders of non-profit Legal Entities may be Bulgarian and/or foreign legal entities and able-bodied natural persons.